Automatic film-shifting device for cameras



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m. HERSHEY AUTOKESIC FILE SHIF-FIHG DEVICE F0331 filed June 19. 922

Patented Mar. 25, 1924.

(1,481,741 PATENT oFFica.

UNITED STATES IRVING HERSHEY, OF DENVER, JOLORADO.

anrouarrc rILm-smr'rmc nEvIcE For. cmnms.

Application .flled June 19, 1922. Serial 80.569421.

To all whom it may concem:

Be it known that I, IRVING cit and county of Denver and tate of Co orado, have invented certain new and useful Improvements in Automatic Film-Shifting Devices for Cameras; and I do declare I the following to be a full, clear, and exact constructed that the operator must place a new film or a new portion of the film into operative position after every exposure. It often happens that the operator forgets to wind" the film so as to guard the exposed portion from another exposure, with the result that two pictures are spoiled through a double exposure.

It is the object of this invention to produce an improvement that can be attached to or built'into any camera of ordinary construction, and which will function to wind a predetermined length of film from one spool to the other when an .exposure has been made, thus making the camera fully automatic in its operation.

In order to more clearly describe my invention, I shall have reference to the accompanying drawing, in which- Fig. 1 represents an ordinary camera having my improved film winding means incorporated therein, parts, being broken away so as to more clearly disclose the mechanism employed; 4 1

Fig. 2 is a fragmentary view of one end of the camera seen in the direction of arrow 2 (Fig. 1);

Fig. 3 is a vertical transverse section taken on line 3-3, Fig. l;

Fig. 4 is a section taken on line 4-4, Fig.

Fig. 6 is a detail on a larger scale, show- HERSHEY, a citizen of the United States, residin at the 'ing the spring motor in its relation to the stop.

The same or similar reference characters will be used to desi ate the same or similar parts throughouttl ii e several views.

Numeral .1 represents the camera as a whole, and as the camera is merely an ordinary camera of well known make, which has been only slightly modified for the purpose ofattaching my improved mechanism thereto', I shall describe only such parts thereof' as cooperate with my improvement. The spool containing the unexposed film is indicated on the drawing by the numeral 2, and the spool for the exposed film is indicated by. numeral 3, while the film is represented bythe part marked 4. The key 5 is the one by means of which the spool 3 is rotated when it is desired to start the film onto the spool 3, or in case the automatic mechanism should fail for any reason to operate. The side of the camera, which is to the top in Fig. 1, and which I shall refer to as the top of the camera, the slight extent shown in will hereinafter be described.

is modified only to Fig. 3, which My mechanism is shown attached to the bottom of the camera. in Figs. 1 and 3, and consists of a casingfi which is secured to the bottom of the cameraby suitable screws or rivets 7. In one end of casing 6 I pivot a tubular bearing 8 which has one end 9 of decreased diameter which extends within the camera. and serves as a rest for the bottom of spool 3. At the juncture of parts 8 and 9 a shoulder is formed which engages the inside of the casing 6, while a collar 10 is se- .cured to the member 8 and cooperates with the casing '6 to prevent lon itndinalmovement of the member. Wit in the tubular member8 is a plunger 11 Which is provided at its upper end with a transverse part 12 which engages a corresponding notch in the end of the spool. A ring 13 is \pivotally attached' to the lower end of the plunger 11 and serves as the means by which plunger 11 may be reciprocatedwith respect to member 8, and by means of which member 8 as well as the spool may be rotated. The upper.

end of part9 has diametrically opposed slots which cooperate with the part 12 to prevent relative rotation of members 9 and 11. Mounted on member 8 is a gear 14 which is provided with a pawl15 which cooperates with a ratchet 16 on member 8 to permit free relative rotation in one direetion only. The

,741 if i one revolutibn to wind the first exposed spool 3 can be rotated by either key 5 Or 13 onto spool 3.

to wind film thereon In drder to automatically rotate the spool 3, I provide a spring '17 and a train of gears, by means of which the power stored in spring l7 will rotate the wheel 14 and spool 3. Thesspring 1'! has one end secured to the shaft 18 on which theaear 19 is non-notatably butslidably mounted; the other end of.

It will be noted that the effective diameter of spool 3 is constantly increasin as the film is wound thereon and as a resu t of this I must provide means whereby the rotation of gear 19 is varied inversely with the effective diameter of the film. As explained above,:arm 32 rests on the film and as the film builds up the pulley 33 is caused to 1'0- the spring-is segured by means 20 toa statate 1n a counter-clockwise direction (Fig.

tionary portionof casing 6. Qn a shaft 21 I mount two idlers 22 and 23, the former of which cooperates with gear 19, and the latter With gear 14. To is apparent that when spring 17;;is under tension and tends to rotate wheel 19 in the direction of the arrow, wheel 14 will tend \to retate in the proper direction for winding the film 4' onto spool 3. Spring 17 must, of course, be of such strength that it will wind the film from spool 2 to spdol 3-whenever it is permitted to operate? In order to prevent the operationv of spring 17 except as and" when desired, I mount rotatably but non-slidablyon shaft 18 a disc 24, which is provided with a stop 25 for engaging a similar stop 26 on gear 19 when the latter tends to turn. A pairbf spaced collars 27 hold the disc 24 4). Therefore, as the film is wound, stop 25 is constantly moving in a, direction eounter to that of gear 19 and permits the latter to rotate less for each film. By properly proportioning pulleys 33 and 29,

the movement of stop 25 can be made to compensate almost exactly for the increased diameter of spool 3, with the result that the same length of film will be wound thereon at each operation.

It is desirable to make the operation ontirely automatic, and I have therefore provided means whereby the operation of the shutter lever 35 will automatically disengage the stops 25 and 26 on its return stroke.

Referring now to Figs. 3 and 4, I have provided a rod 36' 'which is rotatably mounted in bearings 37 and 38 and has one end Q from longitudinal movement on shaft 18, provided with fingers 39 which engage a and aspring 28 tends to hold disc 24 against suitable means on disc 24. When rod 36 is gear 19. It is apparent thatiI must provide slightly rotated, disc 24 will be moved a disc 24 with meansiwhich :will prevent it from rotating when urged to do so by the action of spring 17, and this means is obtained in the following manner. On the upper side of disc- 24 (Figs. 1 and 6) I provide a grooved pulley 29, which has what may" be termed a wire belt 30 wound thereabout suflicient distance to disengage the stops25 and 26. and thus permit gear 19 to rotate. The rod 36 is rotated automaticali by the following means: A plunger exten s transversely of the camera and has one. end rest; ing on the bent portion 41 of rod 36 (Fig. 4)Jand the other end of rod is engaged by 40 and positively anchored thereto at one point. the end of the-bell crank lever 42; When i For this purpose I have mounted shaft 18 the path of lever 35 1n such a manner that it has aJimited longiplunger 45.

A shaft 31, hearing one end bent \atright angles and resting on the film surface on a spool 3, is rotatably mounted and 'previded at its lower endgwith a pulley 33. The belt joins pulleys 29 and 33 in themanner shown in Fig. 43 and any tendency of disc 24 to be rotated by gear 19 is resisted by the wire belt 30 and the stop 32 in the manner clearly apparent from an inspection of Fig. 4;;

I now provide means whereby the disc 24 may be moved away from gear 19 a snficient distance to permit stop .25 to disengage stop 26 so as to permitthe gears to rotate.

' pathibf stop 26 and gear 19 will be permitted to rotate. The button 34 needs to be dean instantaneous exposure is to be made, shutter lever 35 is moved in the direction of the arrow (Figsfi 2"and 3) and rides over and when lever 35 returns through the action of the spring 44, it will rotate bell crank 42 clockwise and move the rod 42 the upper end 43 of the bell crank lever 42,

downwardly, thus rotating rod 36 and deleasing the means which holds the gear 19 from rotating, andpermitting the ears to operate and wind the film onto spoo 3.

When it is desired to take a time exposure picture, the bell crank-lever is held out of by pressure onthe From the above it will appear that I have produced a device whichautomatically shifts the film after every exposure, and which can be applied to cameras of ordinary construcpressed only for an instant and spring 28 tion without appreciably changing the same.

will :cause disc 24 to move back to its original position and to engage stop 26 when gear 19 has made approximately one revolut1on. The ratios of the gears are such that gear 19 willliave to move slightly less than I am aware that the object sought-to be accomplished can be obtained by specifically different means than those shown, and the drawings are therefore merely illustrative of one embodiment and should not be conmeme: i 8

sidered as limiting the inventiontoth'e exact said s 001, said means a stop; a structure shown, as changes can be made secon stop rotating about 0 same axis as within the scope of the appended claim the first stop and in the path thereof, means without departing from the inventive idea for rptatingtsaid second stop in the opposite 15 a disclosed. direction-from the first stop and to an extent, Having now described my invention, what proportional to the amount of film on the I claim 1s spool, said means comtfirising a feeler 'rest- In a camera having a strip of film, a spool in on the surface of e film. for the reception of said film, means for rotestimony whereof I afix my m 30 'tating said spool, said means comprising a ture. spring motor, means rotating in unison with IRVING HERSEEIL 's' 

